Marine Corps Tactical Publication 3-03D, Security Cooperation, is designed to assist Marines at every level in the execution of their duties to prioritize, plan, execute, and assess security cooperation engagements with partner nations in support of U.S. national security objectives. It outlines security cooperation guidance and lexicon and Marine service component planning considerations, such as legal and political considerations, tools and resources, and the Marine Corps’ security cooperation planning and execution process. This publication applies to Marines and civilians across the total force.